Recently, mobile phone units are being rapidly spread, as a mobile communication system develops. A wireless communication device such as the mobile phone unit covers multi-bands and is systemized. A single wireless communication has a plurality of communication devices. For example, a mobile phone unit covering a plurality of frequency bands is known. The mobile phone unit has a plurality of antenna duplexers in order to cover a plurality of frequency bands.
The antenna duplexer is used for separating a transmit signal and a receive signal having a different frequency, and has a transmit filter and a receive filter. Recently, an acoustic wave filter allowing downsizing is used as the transmit filter or the receive filter.
Generally, an antenna duplexer has a structure in which a transmit filter and a receive filter provided in different chips are mounted on a substrate. Recently, in view of simplification of mounting, an antenna duplexer in which a transmit filter and a receive filter are provided in a single chip is being manufactured. Japanese Patent Application Publications No. 2000-349586 and No. 2007-134795 disclose that in a structure in which two or more antenna duplexers are housed in a single package, transmit filters in the antenna duplexers are provided in a single chip, and receive filters in the antenna duplexers are provided in a single chip. Japanese Patent Application Publications No. 2011-9882 (hereinafter referred to as Document 3), No. 2001-267868, and No. H10-190390 disclose that a plurality of acoustic wave filters having an IDT (Interdigital Transducer) electrode having a different thickness and composed of a different material are provided in a single chip.